Ladies, What would you do if you found out your man is liking other girls pictures on instagram and Facebook ?

What do you mean by "liking"? Do you mean liking in terms of admiring, or liking in terms of clicking the like button? There's nothing wrong with the latter. If he's just following other people on social media and likes a photo, there's nothing wrong with that. Whereas if he's fantasizing about them and having a mental affair, that is wrong. But, you also have to put yourself in his shoes. If you saw shirtless male models on Instagram, would you check them out? If your answer is yes, then you both have the same morals.

I wouldn't mind at all because you're supposed to be able to admire beautiful things. I'm not so insecure as to insult myself by being angry that someone I care about can admire beautiful things because after all and that person is admiring me to or they wouldn't be with

ask him why he likes looking at other girls and depending on his answer, break up with him or start looking at guys

I would reclassify him as not "my man" anymore.