The real confusion starts with some people using the expressions 'oral top' and 'oral bottom'.
Some people see this more 'graphic' than others. So, they conclude that 'the oral top' is a sucker guy and 'the oral bottom' is conversely, the guy who is getting his dick sucked.
The others tend to see 'tops' as 'insertive' partners and bottoms as the 'receiving' ones. And the Confusion is complete.
Practical advice: avoid the 'bttm and top' expressions when it comes to oral sex. Expressions like 'looking to be serviced or looking to service' seem to be working just fine.
KD