On Sunday, the on-again couple took their romance to the Los Angeles Zoo and Botanical Gardens, where they spent time visiting the sea otters, elephants and other animals for a few hours.
"They were super cute together," an onlooker tells PEOPLE. On Friday, the duo had a romantic meal at Mastro's and afterwards caught a showing of Think Like a Man Too.
It remains to be seen how long the reunion will last – since initially splitting in November 2012, Gomez, 21, and Bieber, 20, have been on-and-off several times – but a source says the singer has been nothing but a gentleman this time around.
"Justin's extremely doting on her, and there hasn't been one second where he hasn't been touchy-feely and sweet with her," says the insider. "They're pretty inseparable and very affectionate."