William Remmers Dirk is dejected and lost after realizing that he likely has chosen the wrong path. Roelf gives Dallas attention which causes him to feel like "a rubber stamp." Dirk isn't even mentioned present in the next page when they are in the car together and Dallas returns a compliment to Roelf; he is completely sidelined by Roelf who is Selina's surrogate son/partner figure. There is even a bit of narration near the end that directly acknowledges Roelf as her true son. I believe the phone call is just another reminder that evening's party; the Storms are calling to bring him to the party or the like; more of the same old situation with Paula. Poor Dirk is never in the right place and the right time and he can't get his mind together. He just sinks into his bed face down, obliterating the world around him and being left in perpetual ennui. It's a very gently lobbed, but ultimate dour ending, innit?