Showing gratitude for investment is one of the very best tests for male quality that I know of.

When a man you're seeing does something that actually deserves praise (paying for a nice dinner, doing something genuinely thoughtful), let him know you are pleased. Smile, say you appreciate it and thank you. Be genuine.

A LVM will both love this and panic a bit. He will love knowing that he's possibly ''got you'' where he wants you, but more than this be smitten by the fear that he has possibly given you more than he needed to, and could possibly get away with less. As a result, you will see de-escalation, withdrawal, or other bullshit. LVM are ALWAYS thinking of how to ''protect'' themselves from ''being used'', and will cut any corners if he gets to thinking you're a bit too pleased with him. If you're happy with this, you'll be satisfied with less, and that's his important takeaway.

A HVM? Different story. This man will be positively delighted, and keep all that nice shit coming. Your smile, laugh, and words of appreciation are like crack that keep him coming back for another hit. You will see him keep it up, and possibly try to outdo himself to see just how beautiful you look when you're even happier. Accept enough investment, and he will be at your service for life, without mind games or feigning being unimpressed. All to see you smile.

Two important reminders: 1) Reign in your inner pickmeisha and don't over-fawn or blow smoke up his butt about his generousity. Just accept his gifts with pleasure. 2) Keep it under your hat. Don't let on that you're watching how he reacts to your gratitude (or indeed, any other standard of behaviour you're watching for), just sit back, observe, and quietly work it in to your vetting.