"You can tell they're so in love," an onlooker tells PEOPLE
The two – who “aren’t hiding their affection at all,” according to an onlooker – checked into the Delano hotel and are in town to see Ronson’s family.
Monday afternoon, they spent a little more than an hour hanging out at the Delano pool with the entire Ronson clan – a large group of about a dozen people.
“Everyone was having a good time. Lindsay and Sam were very comfortable with the group around. You can tell they’re so in love,” says an onlooker. “Lindsay seemed to really fit in. It seemed like everyone really likes her.”