Neil Patrick Harris' children don't want siblings.

The 45-year-old actor has eight-year-old twins Harper and Gideon with his husband David Burtka, and has said the youngsters have no desire for their fathers to have another child, because they already ''have each other''.

When asked by Us Weekly magazine if Harper and Gideon want siblings, Neil said: ''No. I mean, they have each other. They're twins. So there's a boy and a girl, and they're super stoked together.''

Meanwhile, the 'How I Met Your Mother' star - who welcomed his twins with David via surrogate mother in 2010 - previously gushed over his children when he spoke about their impressive milestones.

He said of his brood in March last year: ''Gideon's into baseball at the moment so he's been practicing his baseball drills and Harper is very into gymnastics still. She loves doing handstands. As do I. We're cut from the same cloth. I'm big up in circus stuff. We keep showing each other handstands [and] she corrects me more.

''We try to incorporate math and spelling and reading and all kinds of things all day long. If they ask if they can have a desert then we'll use numbers to figure out how to do it. 'If we're just going to give you two but there are five, how many are left?'''

And Neil also recently shared the secret to the lasting bond he has with his his husband David, whom he has been in a relationship with for 15 years and married to for almost five.

He said: ''I think the secret to a relationship is just perseverance, you know? It's not always pretty ... but he's pretty, so it makes it easy.''