One Direction's Liam Payne and girlfriend Sophia Smith were spotted sunbathing by the pool in Barcelona, following the couple's rocky relationship earlier this summer. It looks like Liam Payne and his girlfriend Sophia Smith are happier than ever to be together again, especially after a wild night partying at 5 Seconds of Summer Ashton Irwin's 20th birthday party the evening before.

One Direction is currently on tour with 5 Seconds of Summer in Europe, and singers Niall Horan and Liam Payn joined the band for Aussie member Ashton Irwin's 20th birthday party on Wednesday, July 7.

And we're guessing they had a great time, because the next morning 5 Seconds of Summer wrote on Twitter:

Last night was fun :) the band is looking rough this morning lol

— 5 Seconds of Summer (@5SOS) July 8, 2014

The next day, Liam Payne and girlfriend Sophia Smith were spotted sharing a pool chair together and catching some rays. Sophia lounged in a black bikini and a pair of aviator sunglasses, while Liam kept his T-shirt on. A fan caught a photo of the pair:

Liam and Sophia in Barcelona yesterday #3 pic.twitter.com/cSKDHN4cbU — 1D UPDATES (@1DUpdatesOnline) July 9, 2014

The 20-year-old One Direction singer started dating Sophia Smith in July 2013. They dated for eight months before breaking up in May. However, just weeks later Liam posted an Instagram photo of the two of them together. The couple were also pictured leaving One Direction's hotel in Manchester, as well as holding hands and strolling through the streets of the city.