Los Angeles, Nov 5 : Actor Matthew Perry has revealed that his romantic feelings towards 'Friends' co-star Jennifer Aniston "dissipated" when he realised she was interested in David Schwimmer. The actor, 53, said that he "knew what was going on" between his co-stars while they were filming the sitcom, reports aceshowbiz.com. He said on the Jess Cagle podcast on November 3, about his feelings for Jennifer: "But at first it was just like, she would walk in and I'd be like, 'Hey, good to see you!' and I'd go to my dressing room and I'd just go, 'Oh, I'll never be able to be with her.'" He added that he would eventually think about letting go of his feelings for the actress: "All right, that's enough. That's enough. It's been enough now." Anniston, 53, revealed on the 'Friends' reunion show that she had feelings for David, 56, when they were making 'Friends'. Perry added that when he got over Jennifer he developed feelings for his 'Friends' love interest Courteney Cox, as well as their other female co-star Lisa Kudrow. He told 'Good Morning America': "So I made it kind of difficult to go to work, because I had to pretend that I didn't have these crushes." Perry made the admissions on the promotional trail for his new memoir, which details his extreme struggles with alcohol and drug addiction. He has told how he had his first drink at 14 and was drinking every day by 18, before he was taking 55 Vicodin a day. It led to him almost being killed when his colon burst from the drug abuse before 14 surgeries led to him surviving but left him with scars he says he looks at to remind himself to stay clean. /IANS