They should be fine... a m/f
The 2 in my 10 gallon just flirt/flare at eachother through the divider but other than that, they're perfectly fine.
When I first got them, my female Afia would just hang out at the divider staring at Raj, but now... they'll do their little flirting thing for a minute or 2 here and there throughout the day and then the rest they're begging food from me
hehe
If it makes you feel better though go with a divider that they won't be able to see eachother through, or will have a hard time seeing eachother through