And then there's the highly interesting case of Mac. In early seasons, Mac ranged from insensitive (see Charlie Wants an Abortion in which he flip-flops on abortions when he gets a pregnant or The Gang Gets Racist) to narcissistic like Dennis (see The Gang Exploits a Miracle in which he thinks he has the power to bestow blessings upon people; The Gang Finds a Dumpster Baby where he doesn't care whatsoever about Dee's needs; Charlie Gets Cancer in which Mac is disgusted by the transvestite until she appeals to his ego with a flattering comment; Paddy's Next Billboard Top Model in which he decides to award the model title to whomever sleeps with him) or so in need of a validation that he'll take his macho persona to the wrong end (see: Mac Bangs Dennis' Mom in which he desperately wants to be Mrs. Reynolds' boyfriend; The Gang Sells Out in which he appears well-versed on the ins and outs of gay sex; The Gang Gets Whacked in which he's willing to be humiliated just to be part of the gang; or the episodes where he eventually hooks up with the transvestite).
As the series progressed, Mac was developed further as a man desperate for a father figure. His actual father was revealed in "Dennis Looks Like a Registered Sex Offender" to be a prisoner who was absent from his life. This is an angle the show mined well for humor and utilized well in topical situations: Especially in "The World Series Defense" where Mac wants Chase Utley to want him as a dad. It's an explanation that could even be retconned to explain his behavior in past episodes: Perhaps, his mixed-up Catholic beliefs and his desire to be a priest in "Gang Exploits a Miracle" are explained by thinking that he needed God as a father figure at some point in life?
In Season 7, Mac famously became fat without any prosthesis It was a boost to the show's buzz factor. My pet theory here is that in contrast to Dennis and Charlie, the writing team ran out of mileage for Mac as a needy child so they went with another angle.
Which brings us to Season 8 which evidently decided to milk the Mac is gay angle. My theory here is that Mac has always shown a few signs of being gay. As I previously mentioned, the joke at one point was that Mac tried so hard to be Macho that he inadvertently would drift into gay territory. His enthusiasm for role playing with Dennis as the gay lovers Vic Vinegar/Hugh Honey in the Season premiere of Season 5 indicates a desire to be gay with Dennis. This was lampshaded and played with in the episode "Mac and Dennis Break Up."
It seems as of late, viewers whether on message boards or reviews, people have been pointing to Mac's repressed homosexuality. At the same time, that's a joke employed by a very high number of sitcoms (i.e. "Arrested Development", "Three's Company", "Home Improvement", Jimmy Kimmel with Ben Affleck, Conan O'Brien with La Bamba). TV Tropes even has a term for it called Ho Yay
It's even been hinted at by show creator and actor behind Mac, Rob MacElhenney, that Mac is indeed gay.
An imdb user on the topic pointed out the following:
"Having said that, here's my two cents. Mac being attracted to a transexual is not indictative of any orientation. There's a reason they cast a very attractive woman in the role. Notice how the only thing that keeps Mac from committing fully to a relationship is when "her" penis keeps rearing its ugly head (so to speak). And Mac lashing out against gay marriage is not a case of "protesteth too much", it's a case of Mac being angry that Carmen didn't call him after she had the surgery.
As for Dennis, clearly Mac has developed an intense emotional relationship and inter-dependence. It's entirely possible that in Mac's jumbled mind that he has subconsciously confused this with a sexual attraction, and he's not aware of it. "
In the meantime, stronger hints have been dropping. In "The Gang Gets Analyzed", Mac is chewing a pen and knows on a conscious level it's a phallic symbol. AV Club Reviewer Emily Guendelsberger (if you're going to be cited by me in an article, please have an easier-to-spell name, sheesh) teased her review by writing "Mac's Definitely Probably Gay and Other Revelations" In "The Gang Dines Out," Mac gets into one of his usual squabbles with Dennis but I was taken for how effeminate and catty Mac was acting.
My take on it?
There are some episodes before this season where Mac has a clear desire for women and it's ridiculous to argue that he isn't heterosexual. The lengths he goes to get with a woman in "Billboard Model", "Mac Bangs Dennis' Mom", "Charlie Wants an Abortion." So is Mac being written inconsistently?
Like "Fat Mac", I would argue "Gay Mac" is a new continuity-buckling direction the writers want to take Mac. Even more interesting, I am convinced the writers are taking their cue from all the Ho Yay speculation, and decided to have fun with these intense fan speculations that Mac is gay.