His father does not agree to him marrying a girl who is two years older than him

Firstly: 

There is nothing wrong with a man marrying someone who is two years older than him or more, if she is religiously committed and of good character. The Prophet (peace and blessings of Allaah be upon him) married Khadeejah bint Khuwaylid (may Allaah be pleased with her) and she was older than him. 

But the father’s opinion should be borne in mind when choosing a wife for his son, because of his right to be respected and honoured, and because of his experience which the son does not have. But the father’s agreement is not an essential condition of the marriage being valid, unlike the woman whose marriage is dependent on her guardian’s approval. 

Secondly: 

The son should try to convince his father and explain to him how keen he is to marry you. If the father responds, then praise be to Allaah, but if he insists on his attitude, then the son is caught between a rock and a hard place: 

1 – He can give up his own wishes and do what his father wants. This is better for him in most cases, unless the father’s nature indicates that he will never agree to anything for his son except that which he chooses himself, which is not in accordance with the son’s wishes, such as if he chooses someone from within the family or tribe who is not suited to the son, or it seems that his objection is based on the woman’s religious commitment and upright character. In that case the son will have no choice but to go against him, because if he does not go against him today, he will do so tomorrow. 

2 – Or he can do what he wants and go against his father’s wishes – assuming that he can afford to get married by himself. But this should not be done, because it is going against the father and making him angry, and there is the possibility of family ties being severed and enmity being created, which would be harmful for the son and his children, and for you too. The wise woman should not agree to such a marriage, except in cases such as we have mentioned above, which is where the father’s way of choosing a wife for his son usually goes against the son’s wishes and there is no option but to go against him, because some fathers have their own tastes or opinions that do not suit their sons. We advise fathers to allow their sons the freedom to choose, because marriage is a lifelong commitment and a person has the right to choose the person with whom he will share his life. The father’s role is offer advice and guidance, not to force any choice, so long as the son will choose someone suitable. 

The son should try hard to convince his father. We ask Allaah to help you to do all that is good. 

And Allaah knows best.