Can you reference a female character that hasn't been sexually objectified in some way in the series?
You were encouraged to identify Meryl by her ass in MGS1, Sniper Wolf had her suit open and was specifically identified for her beauty in the briefing, Fortune wore a small, tight, latex leotard for some reason, you could make Rose's tits bounce with the controller in MGS4, Snake oogles both Mei and Naomi, the B&B unit were all highly sexual objectified (while being in a haze of mental trauma, so you can fap while their having PTSD flashbacks for extra fun!), there is of course EVA (in both MGS3 and as an old lady in MGS4), and even the otherwise respectabler Boss opens up her shirt to give you an easy view of her cleavage, you could molest the female soldiers in MGS4 (or atleast make them feel molested enough that they turn around and backhand you even though you have a gun on them), and there is of course Quiet who as far as I know is the only female character in MGSV (I didn't play the whole game) and I didn't hear flattering things about Paz.
Literally the only character that I can think of who wasn't put in a situation where they were either inappropriately dressed, oogled, or otherwise had focus brought to their sex is Natasha Romanenko (the only reason that she avoided it is that she was in the game so little that everyone forgot about her and you yourself are probably probably googling her right now to remember who the fuck she is) and I guess maybe Sunny (because she's like 8 and I guess even Kojima isn't skeevy enough to go full pedo, despite Paz)?
I can give your that there was some sexualization going on with male characters, but you can see the disparate frequency between the two gender's sexualization.