What is the most accurate conclusion that can be drawn about Algernon based on Jack’s words?

Read the excerpt from Act III of The Importance of Being Earnest.

Jack. I fear there can be no possible doubt about the matter. This afternoon during my temporary absence in London on an important question of romance, he obtained admission to my house by means of the false pretence of being my brother. Under an assumed name he drank, I’ve just been informed by my butler, an entire pint bottle of my Perrier-Jouet, Brut, ’89; wine I was specially reserving for myself. Continuing his disgraceful deception, he succeeded in the course of the afternoon in alienating the affections of my only ward.