AITAO if I tell my girlfriend I don’t want her to go to dinner with her boss?

Girlfriend has a sales incentive that includes “a suit and steak dinner with the boss.” Suit would be dress in her case. But I feel uncomfortable with her going alone to a dinner with her boss. Especially if it’s alone and he’s buying her a dress. I want to be supportive of her job, but this just feels weird to me. How should I approach this and still sound supportive of her job