This past Christmas, Simpson, 23, surprise-gifted Wentz, 28, with the present of his dreams: a 2008 Triumph Bonneville motorcycle. But she's not getting on it until he masters the bike.
"When we went to get it, I bought my helmet and I was like, 'You should probably buy a helmet, so we can ride together,' " Wentz, hosting the Wayne Hadly Collection preview at Scout in Los Angeles, tells PEOPLE.
"She was like, 'I'm not going to buy a helmet, I'm not going to ride with you, until you actually know what you are doing!' "
Turns out, Simpson may know best. "I was riding yesterday," Wentz said with a chuckle. "I didn't realize how hard a motorcycle was to ride. I'd only seen it on TV, and in movies, and I was like, "I want to ride one!", but they're f------- hard to ride!
Meanwhile, what his his Christmas present to her?
"I got a tattoo," said the bassist, proudly showing off the ink on his left arm. "It's the lyrics of a song ... 'Honey Is For The Bees, Silly Bear. It's this lullaby that I wrote for her. And I got her jewelry."
He added, "But I didn't beat her motorcycle present."
Male BondingAt another event over the weekend – the opening of the Madden brothers' DCMA Collective store in Los Angeles – Wentz talked about what it's like going on double-dates with Ashlee's sister Jessica and her boyfriend, football star Tony Romo. Turns out, the guys bond over music.
"Usually we talk about eighties rock," said Wentz, who is collaborating on a t-shirt design with DCMA. "That's our bonding experience. We agree on 'November Rain.'"
So, What's the agreement? Said Wentz: "That it's awesome!"
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