Advice please!?

I been with my boyfriend for a year, but before that I knew him for years. I worked with him at my old job, and everyone there use to brag about girls and all and and he use to say he slept with girls all the time at parties and all and talked to all these girls and blah blah blah. Then I questioned him on it, because we both left and work elsewhere now and he said he did it to fit in because he was a loser and made fun of his whole life. He said he lost his virginity to his ex, and was shy his whole life. His mom kind of said the same thing, and same as friends of him as I read old messages of him they were making fun of him for being a virgin. However, at my old job he told me he hooked up with girls and did all this stuff. Now he says he did it to be cool and fit in. Even with a. girl that worked there and quit he said he did stuff with her now he denies it and swear on his whole family, that he only had sex with one other girl. Do guys usually do this type of thing? Advice?