Harry (18) appeared to take it all in his stride as he met Taylor's mum at the singer's home in Los Angeles.
The trio popped out to do some grocery shopping at local supermarket Ralph's.
Harry had stayed over at Taylor's house the night before.
Harry and Taylor began dating after meeting backstage at a rehearsal for the US X Factor.
Since then they have been enjoying a whirlwind romance.
Friends of Harry, including BBC DJ Nick Grimshaw, say he is smitten with Swift.
And now it seems that Taylor's mum has given the 1D star the nod of approval.
Harry flew over to visit Taylor and her family after celebrating bandmate Louis Tomlinson's 21st at a secret bash in the UK.
The former X Factor contestant showed off a new ship tattoo on his shop visit with Taylor's mother.
Country singer Taylor joined Harry earlier in the week when he spent four hours at LA tattoo parlour Shamrock getting a large warship tattooed on to his upper arm.
Taylor chatted with the tattoo artist, held Harry's hand and played pool while he was under the needle.
Harry's new tattoo, which resembles Nelson's HMS Victory, is a replica of the one seen on Taylor's boyfriend in her video I Knew You Were Trouble.
Harry is a big fan of getting inked-up -- he has had more than 20 tattoos since turning 18 this year.