Hold everything, folks.
While it is still (unfortunately) true that sexual orientation is not protected under Federal law or under the laws of the OP's state, there is case law at the Federal level which makes same-sex sexual harassment illegal. I used to know the case law off the top of my head but it's been while and I'll have to go looking for it.
telling me the size of his penis, or talking about sticking something in my butt,
Any of you planning to tell me you wouldn't be calling this SH if the poster were female?
OP, if you have not already done so, IMMEDIATELY go to HR and report this as harassment. It's more difficult because it's a client and not a co-worker or boss, but it's not as dire an outlook for you as my colleagues are trying to tell you, either.
Maybe I didn't explain the situation right but you seem to understand what I was saying. The profanity and dirty joking back and forth does not bother me and I know should have not gotten caught up in that at all, but the first week I started working for him he's dropping F bombs and using gay slurs, so I was just like "whatever", he's the boss. I do not engage in this type of communication to anybody else in my working environment. His come on's and nasty gay remarks are what I dislike. I told him he was sickening because he was telling me about getting "his salad tossed".