I think that when using a computer at work for non-working purposes it's irrelevant whether it's tennis forum or gay fitness site. If somebody is gay or wants to go to gay pages - why should she/he be discriminated because of it? Why do you feel embarassed? Nobody's business what pages you are browsing, and when you're supposed to work or do classes that time, being caught with opened Wimbledon livescore can be equally harmful.
And honestly, I find these banners rather
but in a hilarious way.