Hi Sophie,
I used to get the same thing at the gym, at first, until the guys got to know me better and realised that I actually knew what I was doing. I was the only woman hanging out in the free weights section (that was a good 15 yrs ago btw).
A lot of women went to the machines area and, of course, in the cardio classes, etc... but none of them ever walked through to the free-weights area.
Same deal with the gym that we had at work - I was the only woman who ever set foot in the weights area. I trained there for a few years and I was the only one the whole time.
I really enjoyed training there and the guys were always helpful when I needed spotting, etc... they understood that I was there to train, just as they were. It was great
The men have all, always been super nice and very helpful. If women knew this, I think they'd go more... I think a lot of women are shy and don't know enough about lifting weights etc... and (gasp...) are afraid of bulking up (I could strangle some of the women when I hear them say that... It drives me nuts)
We have moved across the country now and I train at home. I'm expanding my home gym little by little - no time to go to a gym right now but I might go back eventually... I'm coming back to my love of weight training after a couple of nasty injuries back to back (nasty foot injury & I damaged 3 facet joints in my spine - not while working out btw and that one still bugs me after a couple of years of rehab work).
But all this to say that I'm starting to show some definition and I've got men that come over to say "hello" at the grocery store on a regular basis now!
And I'm not even dressed in the kind of outfits I'd wear to workout at the gym... and even the wedding ring doesn't seem to stop them hahahaha
The guys here are right, just tell the men at your gym that you're a serious lifter and that you look forward to training with them and that hopefully a few of them will be able to spot you from time to time. They'll be happy to help you and they will see you as a "bodybuilder" rather than just "a woman".
All I can say is that the majority of the guys lifting weights in gyms are super nice and they're the best kept secret ever!