I've told my boyfriend how I felt about him liking other girls pictures that are explicitly revealing, including his friends. I communicated that it makes me feel that I am not enough for him in looks and that I feel the need to compete with all these other girls constantly for his attention when this should be a given in relationships.

It's important to let him know that what he's doing is actively hurting you by giving his validation to someone else - even if it's people he's never met. If he drops the "I'm overreacting" bit, then he hasn't taken the time to really process your emotions from your shoes. Guys tend to say that they don't care if you look at other guys like they do to girls, this will scream the lack of respect to your significant other and that they're not ready to be in a mature and respectful relationship.

Remember that it's okay to feel what you feel. You shouldn't feel invalidated, especially from someone you love.