Prince Harry and Meghan Markle's latest engagement didn't quite go to plan

And it was all thanks to the British public transport system

Meghan Markle and Prince Harry have stepped out on their third royal engagement together, and they looked as adorable as ever.

The couple arrived in Cardiff this afternoon, where they'll visit Cardiff Castle before hearing performances from musicians and poets, meet sportsmen and women and see how organisations are working to promote the Welsh language and cultural identity.

Meghan, 36, had perfected a smart-casual look in an all-black ensemble, wearing a Stella McCartney wrap coat with an oversized fabric belt, skinny trousers, scarf and boots.

Her hair had been styled into a chic loose bun, a look she first rocked at Reprezent Radio in Brixton radio station last week.

Harry, 33, had also gone for a monochromatic outfit, choosing blue chinos, jumper and a jacket.

The couple - who are set to get married on 19 May - were beaming as they met crowds of well-wishers.

But they'd actually had a pretty stressful journey from London, as train delays meant they were late to arrive in the Welsh capital.

A Great Western Railway spokesman told MailOnline they couldn't comment on individual travellers, but explained that trains to Cardiff were delayed because of a 'Network Rail infrastructure issue, namely a points failure at Didcot, which has impacted services'.

Kensington Palace acknowledged the hiccup, tweeting: 'Thank you so much to everyone who has waited to welcome Prince Harry and Ms. Markle to Cardiff.'

At least Meghan's getting used to British transport, eh? And despite the fact that royal fans had been waiting in the cold since 6am, they soon seemed to perk up when they set eyes on the loved-up couple.

We mean, how could you not?! Bring on the wedding.