LOVE & MARRIAGE:{MONEY & GAIN}
1.. MR B is keen for marriage to take place between Gerald and Sheila as Gerald is the highest classed man in the play - using his daughter as a business transaction to increase his social standing and to benefit his business; "There will be a time when Birlings' co & Crofts Limited will be rivals no more."
2.. MR B'S motives for marrying MRS B - yet again was for his selfish gains of status and power. this is evident as their marriage lacks affection - "You'll have to get used to that, just as I had." [MRSB -> SHEILA]