Heads up charging a flush draw.

[Mclane665]

Weekly £25 tourney at the local casino. Stacks are pretty even. both with around 70-75K blinds are 3K-6K no ante. I have not played with this guy before but had him at the last two tables. Strange player either calls folds or all in no other types of raise. I have seen him pay to hit flushes against the odds throughout the last two hours. He has done it once already HU and hit on the river.

Hero is button with A9os I make min raise and villain calls. Flop is 379 2 diamonds. Villain hecks I bet 65% of the pot and vilain calls. Turn is an A none diamond. Here is where I get a little confused. I have top two and Im 80% sure he is on a flush draw. if he checks to me do I make it maybe %70 of pot and being pretty sure he will call or go all in and maybe he calls maybe he folds. The only card he will bet the end is a diamond and the only diamond I like is the A for a boat.

I was really torn on this one would be very greatful for some advice on what was the best play and why?

Thanks in advance
Greg