I feel so guilty after masterbuating

So the only way I(f18) get wet is by like actually doing it with someone otp or being talked through it otp. So this dude I haven’t know long but he asked if i wanted to feel better and I’m like sure ig. So we did it then we stayed otp 20 mins but didn’t talk then he hung up cuz it was like 3am. I’ve been feeling so guilty since I woke up but I asked him today how he felt abt last night and he said it was good he just wanted to make me feel better. I told him I feel guilty and he said I shouldn’t but I do and idk what to do. When I had sex before I didn’t feel guilty after doing it but when I do it otp with someone or send nudes I feel extremely guilty.