So the first examples I can think of are when I've been with my ex girlfriend, we've been out and about and guys will clearly see that she is with me, yet it wouldn't stop them or bother them from flirting with her in front of me, hitting on her and trying to take her home or whatever. They'd completely act like I was invisible, or alternatively would gain like pleasure from watching me say something by completely disregarding me and still going after my partner. I've experienced this from both complete strangers and people that i've been familiar with and spoken with on a regular basis at school or been working with. They literally have no respect for how uncomfortable they make either myself or my partner at the time feel. The worst it's been was a guy actually then planted a kiss on her because 'her girlfriend didn't matter'. Then it's also gone the other way - guys have asked for a show and a demo with my girlfriend and wanted to see us 'in action' which, well, no one really wants to hear.
The last example I have is slightly different but I was out on a date with a guy called Doug who was the brother of one of my old work colleagues, Stu, it was going well all things considered and I had met some of his friends on our second date. On this evening one guy was essentially jealous of the fact that i was dating his best friend. He asked Doug a lot about me and he had mentioned I had been with women previously. He then spent the entire evening calling me 'a lesbian fucking feminist' and making me feel uncomfortable by arguing with me over nothing, including the fact that I don't like the taste of milk? He blames this on my 'stupid feminist beliefs' At the end of the evening we walked down an alley way to get home and he made a joke about how he could easily rape a woman down there. I challenged him on this as I was the only female there with three men and didn't think it was on. He then screamed in my face, told Doug to 'put his woman in her place' and then smashed a glass in my face and ran away leaving me bleeding in the street! He has since been back in contact with Doug and Stu and they have made it impossible for me to press charges as the absence of a witness statement has made the case fall through.