It is always scaring to try out something new in life and that includes sex actions as well.
When the dude only started talking about anal sex, his girlfriend confessed that she was very scared of that idea but then she decided to surrender to his hunger for sex experiments and to allow him to fuck her tight asshole but asked him to be very gentle with her asshole. The dude was excited about such a chance and moved on to caressing her naked body with his strong hands and tongue.
He stretched her blind eye and, when it was ready, he stuffed it with his erected dick.