You should find a way to please both of them, e.g. in your case consider having a conversation with them and explain your situation.
In general, if obedience to both is mutually exclusive, then the mother has precedence over the father, provided obviously that obeying her will not involve disobedience to Allah. This is the view of the majority.
أما إن تعارض برهما في غير معصية , وحيث لا يمكن إيصال البر إليهما دفعة واحدة , فقد قال الجمهور : طاعة الأم مقدمة ; لأنها تفضل الأب في البر
But if there is a conflict in obeying the parents in other than sin, such that both can not be obeyed simultaneously, then the majority say: obedience to the mother takes precedence; because the mother has preference over the father in good treatment
— الموسوعة الفقهية
That the mother's right is greater is apparent in the the verse of the Quran that has placed separate emphasizes on good treatment of her on account of her sacrifices:
ووصينا الإنسان بوالديه حملته أمه وهنا على وهن وفصاله في عامين أن اشكر لي ولوالديك إلي المصير
And We have enjoined upon man [care] for his parents. His mother carried him, [increasing her] in weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination.
— Quran 31:14
Hadith also evidence the greater right of the mother:
عن أبي هريرة رضي الله عنه قال جاء رجل إلى رسول الله صلى الله عليه وسلم فقال يا رسول الله من أحق الناس بحسن صحابتي قال أمك قال ثم من قال ثم أمك قال ثم من قال ثم أمك قال ثم من قال ثم أبوك
Narrated Abu Huraira:
A man came to Allah's Messenger (ﷺ) and said, "O Allah's Messenger
(ﷺ)! Who is more entitled to be treated with the best companionship by
me?"
The Prophet (ﷺ) said, "Your mother."
The man said. "Who is next?"
The Prophet said, "Your mother."
The man further said, "Who is next?"
The Prophet (ﷺ) said, "Your mother."
The man asked for the fourth time, "Who is next?"
The Prophet (ﷺ) said, "Your father. "
— Bukhari and Muslim
إن الله يوصيكم بأمهاتكم، ثم يوصيكم بأمهاتكم، ثم يوصيكم بأمهاتكم، ثم يوصيكم بآبائكم، ثم يوصيكم بالأقرب فالأقرب
Allah enjoins you to be dutiful to your mothers. Then He enjoins you to be dutiful to your mothers. Then He enjoins you to be dutiful to your fathers. Then He enjoins you to be dutiful to your next closest relative and then to your next closest relative.
— Al-Adab Al-Mufrad