JoJo Siwa 'Dumped' Kath Ebbs After Allegedly Asking to Marry Them

JoJo Siwa split from her partner Kath Ebbs after her time on "Celebrity Big Brother" in the UK ... with Ebbs claiming the dumping came at the 'CBB' after-party -- even though they say JoJo asked to marry them in the past. Ebbs -- an Australian…