But the actor made sure his wife knew she's the only leading lady in his life on Wednesday after he spent the morning filming scenes with another attractive brunette woman.
The 54-year-old star – who married to Hilaria Thomas on June 30 - was spotted on the streets of New York City with his spouse, taking their puppy for a walk.
His true love: Alec Baldwin bent down to give his wife Hilaria Thomas a kiss on Wednesday after a day on set
Hilaria, 28, reached up on the tip of her toes to press lips with the screen star.
Alec donned loose jeans and a dark jacket while the Pilates instructor was dressed for a work-out in a slouchy grey top over a racer back fluorescent green vest.
Down time: He was taking his puppy for a walk with his new love
While filming scenes for the flick, which also stars Cate Blanchett, Peter Sarsgaard and Sally Hawkins, he got close to his unidentified co-star.
Wearing a smart suit for the role, he cuddled up to the actress, who was dressed in a yellow linen dress with a brown belt and matching heeled shoes.
Getting close: Baldwin had a close encounter earlier on the set of Woody Allen's summer project movie
In character: The actor was dressed up in a suit while his co-star donned a yellow dress and a belt that matched her shoes
Hilaria is the second wife for Alec, whose nine-year-marriage to Kim Basinger ended acrimoniously in 2002.
The former couple share a 16-year-old daughter, Ireland.
Between takes: The film's director Woody Allen was also on set
Speaking to Hilaria? Baldwin was spotted taking a phone call on set
All in a day's work: The screen star is on his second marriage