SHOULD I BREAK UP WITH HIMM!!!! ?? :OO?

ok, me & my boyfriend h been going out for 7 months we have been in a couple of fights and NONE of the times i cause the fight.. it was alway something he did..... a BIG thing he did yesterday i found out he was on omeagle with this girl asking to see her and for pics and ****...... i asked him bout iit he told me it was him & a friend screwing around with her but im not soo sure i believe him :ooo, i dont think his friend (auston) even exxcits cause i NEVER EVER heard of him && my boyfriend dont have no auston on his friend list on facebook... Do you think i should break up with him or just drop it and forgive himmm ? I REAALLY NEED HELLPP :O pleaseee ...... im deeply inlove with him and he would be KILLED if i break up with him casue he would be SOOOO SADDD cause i know he loves me soo much but im not sure hes faithful to me :oooooooooo helpp me PLEASEEE !!!!