The 29-year-old actor was drinking in the Culloden Hotel in Belfast, Ireland, when he was spotted by a crowd of lively wedding guests, who made him join in the celebrations, reported Female First.
Attendee Jamie Reid said, "I plucked up the courage and went over and said he was going to get mobbed by about 20 girls, he is such a quiet guy and he was a bit taken back by it, all these girls."
Pattinson was in Ireland filming his next movie "The Lost City of Z", and took some time to take photographs with the lucky bride and groom, Tom and Sarah Lenihan, and the excited guests before being "moved" on by hotel security.