Almost definitely, it's my girlfriend being aggressive in bed, whether with cuddling or sex. Having my hips played with will really do the trick. xD Other than that, it's all up to my mind to decide when I feel more or less feminine. I really just now started realizing who I was, so I lack the experience and materials to otherwise reinforce my girly state of mind.
The thing that drives me away though... is definitely my masculine face in the mirror. Ugh. Still have yet to try makeup though. .~.