How to tell my boss that I really feel awkward around her when she and this

colleague PDA? Well she is VERY affectionate. She hugs me and kisses me all the time but when no one is watching it. She is very careful about who's around when she kisses me. She avoids kissing me in front of THIS colleague but then when she briefs up she holds that FCUKER'S hand, caresses his chest and what not. I feel really awkward and think that she's a big show off. She likes to show off it to me just because I am single. Whenever she tries to show off I avoid her but she forces me to watch by telling me "Oi where you going? briefing is not done yet!" I may be jealous but still is it appropriate for her to do this? What should I do? Should I avoid her or tell her my concern? Is she a slag? Gosh my brain is exploding with questions!!