I'm sure there's plenty of locker room BS going on for women trying to get into tech but I think it has more to do with the fact that there are so few women who go into tech. Guys in an all male team tend to fall into kind of a frat boy type of social dynamic.
The engineering team I'm on has over 20 people, all male, mostly black (so being white, I'm definitely the odd man out). We would definitely give illegal preference to a female applicant if we ever got any who were qualified, but in over 20 years so far we've had a grand total of 1 female apply and she was not even close to qualified. If she had been, things might have gotten awkward for awhile since we'd almost certainly have to watch what we say more than we do now. There are some women on other technical teams that I work with pretty closely and have no issues with but they tend to have kind of a tomboy type of "just one of the guys" sort of attitude so they get along well with teams that usually range from about 80-100% male.
Even among the women I do collaborate with on a regular basis though, there is a lot less joking around than doing the same job with a male colleague. Some of it may just be an abundance of caution, but the general perception is that if I say the wrong thing to a guy he'll shrug it off and ignore it or tell me to F off. If I say the wrong thing to a woman I get to talk to HR. I'm sure that's not the case for plenty of women but it's not worth the risk. So I'm all business with women. I'm much more casual with guys.
I've heard the dynamic is similar for men going into fields dominated by women, like guys going into nursing being laughed at for working a traditionally feminine job, etc. I don't work in health care though so I don't know how true that is.
