While random chicks are accusing Justin Bieber of being their baby daddy … his mentor Usher may be facing a few “daddy” issues of his own.

The R&B singer’s ex-wife Tameka Raymond has filed court documents in Georgia asking a judge to strip him of joint physical custody of their two children.

Tameka also claims Usher is required and has failed to:

– get her approval before hiring nannies
– give her first shot to watch the kids when he’s away for more than 8 hours
– allow her to take the kids for 2-weeks in the summer of 2011
– let her have custody of the kids during Christmas break 2010

Tameka also claims Usher closed her Saks 5th Avenue credit card — which he specifically said he wouldn’t do — and now she can no longer take advantage of the “special benefits” the card offers.

According to the docs, Usher also promised to pay $5k per month so Tameka could hire her own nanny for the kids — but he hasn’t paid in months, and now owes $34,000 worth of payments.

Tameka also claims there has been a “substantial change in [Usher's] income” since they got divorced — and because of his success, she should get even more money for child support.

A hearing on the matter is scheduled for Wednesday.

[TMZ]

Ironically … Tameka recently uploaded a video of the oldest child — Usher V — sliding down the outer rail of a flight of stairs. (That’s definitely a great demonstration of good parenting!)